I think this was made because of the timeline confusion in Fate/Grand Order Zero. People kept saying Assassin Kiritsugu and Grail Irisviel were not related yet Grail Irisviel remembered the other dimension leading to more confusion. I think the plot was a loop plot yet everyone skipped over that.
Different People
(Similar to Shirou and EMIYA)Gives the Greatest Curse in the World
(Luck Increases Explosively)Fate/Grand Order
(Accel Zero Order event)Fate/ZeroIri summoned from a timeline where the Emiya Family live happilyFate/kaleid liner PRISMA☆ILLYAFate/tiger colosseumCarnival PhantasmKiritsugu summoned from the Fate/Zero timelineIri of a world where Kiritsugu was not needed by the Einzbern (Protected by Chaldea)They have the same memories, but they are not the same personCannot see herKerryIri (Dress of Heaven)29 years oldDivided Spirits (Derivation)Emiya KiritsuguAccel Zero Order IriDerivationJiji-tsugu
Old man tsuguHanafudaGag TimelineKnows him
(and watches over him)Black Holy GrailDifferent PeopleFive Years LaterAssa-Emi
Assassin EmiyaPri-tsugu
Prisma KiritsuguIri-shishou
Master IriDoesn't know her
(but is curious about her)Fire Outbreak Timeline
(caused by the Black Mud)CuteFate/stay nightCute Emiya CouplePost-Fire Outbreak Timeline
(caused by the Black Mud)Pri-Iri
Prisma IrisvielDry-timeline Pri-tsugu
Prisma Kiritsugu「Affection of the Holy Grial」An in-game Active Skill that Emiya Assassin can useEmiya Couple
Relationship Chart
Based on personal interpretationUnder 16 years old
(since Shirley was 16 years old)Got to know each other in the storyFourth Holy Grail WarCopySame Person9 years old
(moveable number of years)
By the way, Zero-Illya is 8 years oldSame Person (maybe...)Einzbern Consultation RoomDeveloped into the Vessel for the Holy Grail (dead)DiscardedIriStarting Point
